The present disclosure relates to a head mounted display, motion detector, motion detection method and image presentation system.
Recent years have witnessed the progress of technological developments for presenting three-dimensional images, with head mounted displays capable of presenting three-dimensional images with depth becoming pervasive. A head mounted display is worn by the user, the viewer, in such a manner as to cover both of his or her eyes and move along with the motion of the user's head. Therefore, by tracking the motion of the user's head and feeding back the result thereof to the image of a virtual space presented by the head mounted display, it is probably possible to present the user with a high immersive sensation and sense of presence to the virtual space.
Further, a head mounted display is worn by the user, the viewer, in such a manner as to cover both of his or her eyes. Therefore, it is difficult to see the real image of the outside world such as his or her hand with the head mounted display on. On the other hand, if the motion of the user's hand can be tracked, it is probably possible to use instructions, each defined in accordance with a type of motion thereof, for controlling the head mounted display itself and the image presented.
The nine-axis approach designed to measure three-axis acceleration, three-axis angular velocity and three-axis geomagnetism is among known approaches for tracking the motion of a head mounted display. This approach has difficulty tracking the motion due to geomagnetic dip depending on the region and may be susceptible to surrounding magnetic fields such as those produced by steel frames of buildings and motors. Further, there are demands for development of a small and compact device adapted to detect the motion of the user's hand which permits intuitive operation by the user.
In light of the foregoing, it is desirable to provide a technology for detecting the motion of the user wearing a head mounted display.
According to an embodiment of the present disclosure, there is provided a head mounted display. The head mounted display includes an enclosure and imaging element. The enclosure accommodates a presentation section adapted to present a three-dimensional image and is located in front of the eyes of a viewer when worn on the head of the viewer. The imaging element is provided in the enclosure and turns light external to the enclosure into an image. Here, the imaging element images light that is vertically downward relative to the enclosure and forward in the direction of line of sight of the viewer when the enclosure is worn on the head of the viewer.
According to the embodiment of the present disclosure, there is also provided a motion detector. The motion detector includes an image acquisition section, bright spot detection unit, vector acquisition unit, pitch acquisition section and yaw acquisition section. The image acquisition section acquires an image captured by an imaging element attached to the head of a user by imaging infrared light radiated by a light-emitting element that moves along with the motion of the user's hand. The bright spot detection unit detects a bright spot of infrared light in the image captured by the imaging element. The vector acquisition unit acquires a vector having, as an end point, the bright spot detected by the bright spot detection unit, and, as a start point, the center of the image captured by the imaging element. The pitch acquisition section acquires, as a pitch of the light-emitting element relative to the imaging element, the length of the vector acquired by the vector acquisition unit. The yaw acquisition section acquires, as a yaw of the light-emitting element relative to the imaging element, the declination of the vector acquired by the vector acquisition unit.
According to the embodiment of the present disclosure, there is also provided a motion detection method. The motion detection method causes a processor to perform a step of acquiring an image captured by an imaging element attached to the head of a user by imaging infrared light radiated by a light-emitting element that moves along with the motion of the user's hand. The motion detection method causes the processor to perform another step of detecting a bright spot of infrared light in the acquired image. The motion detection method causes the processor to perform still another step of acquiring a vector having, as an end point, the detected bright spot, and, as a start point, the center of the image captured by the imaging element. The motion detection method causes the processor to perform still another step of acquiring the length of the acquired vector. The motion detection method causes the processor to perform still another step of acquiring the declination of the acquired vector.
According to the embodiment of the present disclosure, there is also provided an image presentation system that includes a head mounted display and a light-emitting element attached to a grip section gripped by a viewer and adapted to radiate infrared light. Here, the head mounted display includes an enclosure, imaging element and motion tracking section. The enclosure accommodates a presentation section adapted to present a three-dimensional image and is located in front of the eyes of the viewer when worn on the head of the viewer. The imaging element is provided in the enclosure and images infrared light radiated by the light-emitting element that moves along with the motion of the grip section. The motion tracking section tracks the change in relative position of the light-emitting element with respect to the imaging element by analyzing the infrared light image captured by the imaging element.
According to the embodiment of the present disclosure, there is also provided a program that causes a computer to implement the steps of the above method.
This program may be provided as part of firmware incorporated in equipment adapted to basically control hardware resources such as video, audio, gaming equipment and head mounted display. This firmware is stored, for example, in a semiconductor memory such as ROM (Read Only Memory) or flash memory provided in the equipment. A computer-readable recording media storing this firmware program may be provided to supply this firmware or update part of the firmware. Alternatively, this program may be transmitted via a communication line.
It should be noted that any combinations of the above components and any conversions of expressions of the present disclosure between “method,” “device,” “system,” “computer program,” “data structure,” “recording media” and so on are also effective as modes of the present disclosure.
The present disclosure provides a technology for detecting the motion of the user wearing a head mounted display.